Biological buffers with wide buffering ranges

ABSTRACT

Amines and amine derivatives that improve the buffering range, and/or reduce the chelation and other negative interactions of the buffer and the system to be buffered. The reaction of amines or polyamines with various molecules to form polyamines with differing pKa&#39;s will extend the buffering range, derivatives that result in polyamines that have the same pKa yields a greater buffering capacity. Derivatives that result in zwitterionic buffers improve yield by allowing a greater range of stability.

This application is a continuation in part of application Ser. No.12/151,899 filed May 9, 2008 now U.S. Pat. No. 7,635,791. Thatapplication claimed priority from U.S. Provisional Patent applicationNo. 61/124,586 file Apr. 17, 2008. This application also claims priorityfrom U.S. Provisional Patent application No. 61/135,058 filed Jul. 16,2008. Application Ser. Nos. 12/151,899, 61/135,058 and 61/124,586 arehereby incorporated by reference.

BACKGROUND

1. Field of the Invention

The present invention relates generally to the field of amines and moreparticularly to a classes of amines used as buffers in biologicalsystems.

2. Description of the Problem Solved by the Invention

Amines are very useful compounds in the buffering of biological systems.Each class of amine has various limitations which require choosing anamine based on multiple factors to select the best amine. For example,pH buffering range is typically most important, but issues of chelation,and pH range stability, and solubility also come into play. Typically, asuboptimal buffer will result in yields that are well below thepotential yield. The invention disclosed improves the yields infermentation and purification, and improves shelf stability of proteinsand amino acids.

SUMMARY OF THE INVENTION

The present invention relates to amines and amine derivatives thatimprove the buffering range, and/or reduce the chelation and othernegative interactions of the buffer and the system to be buffered. Thereaction of amines or polyamines with various molecules to formpolyamines with differing pKa's will extend the buffering range,derivatives that result in polyamines that have the same pKa yields agreater buffering capacity. Derivatives that result in zwitterionicbuffers improve yield by allowing a greater range of stability.

DESCRIPTION OF THE FIGURES

Attention is now directed to the following figures that describeembodiments of the present invention:

FIG. 1 shows the derivation of polyamines and zwitterionic buffers fromtromethamine.

FIG. 2 shows the derivation of zwitterionic buffers and polyamines fromaminomethylpropanol.

FIG. 3 shows the reaction of 2-methyl-2-nitro-1-propanol withacrylonitrile and its derivatives.

FIG. 4 shows the reaction of 2-nitro-2-ethyl-1,3-propanediol withacrylonitrile and its derivatives where x, y, and n are all integerswhere x and y are chosen independently, such that x+y=n and n is greaterthan zero.

FIG. 5 shows the reaction of 2-nitro-2-methyl-1,3-propanediol withacrylonitrile and its derivatives where x, y, and n are all integerswhere x and y are chosen independently, such that x+y=n and n is greaterthan zero.

FIG. 6 shows the reaction of tris(hydroxymethyl)nitromethane withacrylonitrile and its derivatives where x, y, z, and n are all integerswhere x, y and z are chosen independently, such that x+y+z=n and n isgreater than zero.

FIG. 7 shows the reaction of 2-nitro-1,3-propanediol with acrylonitrileand its derivatives where x, y, and n are all integers where x and y arechosen independently, such that x+y=n and n is greater than zero.

FIG. 8 shows the reaction of 2-nitro-1-butanol with acrylonitrile andits derivatives.

FIG. 9 shows FIG. 9 shows alkoxylation of aminomethylpropanol.

FIG. 10 shows the synthesis of a very mild, high foaming, surfactantderived from MCA and the synthesis of a very mild, high foaming,surfactant derived from SVS.

FIG. 11 shows the synthesis of a series of buffers with 2-nitropropaneas the starting material.

FIG. 12 shows FIG. 12 shows the synthesis of a series of buffers with1-nitropropane as a starting material where n and m are integers wherem+n is greater than zero and n is greater than or equal to m.

FIG. 13 shows the synthesis of a series of buffers with nitroethane as astarting material where n and m are integers where m+n is greater thanzero and n is greater than or equal to m.

FIG. 14 shows the synthesis of a series of buffers with nitromethane asa starting material where x, y, z and n are integers and x+y+z=n and nis greater than zero.

FIG. 15 shows the synthesis of a series of zwitterionic buffers based onacrylic acids.

FIG. 16 shows the synthesis of a zwitterionic sulfonate based ontromethamine.

FIG. 17 shows the synthesis of a zwitterionic sulfonate based onaminomethylpropanol.

FIGS. 18-25 show the synthesis of families of zwitterionic buffers fromnitroalcohols.

FIG. 26 shows the synthesis of zwitterionic buffers from morpholine.

FIG. 27 shows the synthesis of zwitterionic buffers from hydroxyethylpiperazine.

FIG. 28 shows the synthesis of zwitterionic buffers from piperazine.

FIG. 29 shows the synthesis of zwitterionic buffers from ethyleneamines.

FIG. 30 shows the synthesis of a zwitterionic buffer with primary,secondary, tertiary, or quaternary amine functionality.

FIGS. 31-33 show the synthesis of mild zwitterionic surfactants fromnitroalcohols.

FIGS. 34-38 show the synthesis of polyamines from nitroalcohols.

Several drawings and illustrations have been presented to aid inunderstanding the invention. The scope of the present invention is notlimited to what is shown in the figures.

DETAILED DESCRIPTION OF THE INVENTION

Combining amines with monochloroacetic acid (MCA) or sodium vinylsulfonate (SVS) results in products are zwitterionic buffers that canbuffer in both acidic and basic pH conditions. A limited number aminesare currently used for this purpose, such as, tromethamine and ammonia.The reaction of amines, alcohols, and aminoalcohols with acrylonitrile(via the Michaels Addition), followed by reduction results in amines andpolyamines that have a broad buffering range. The further derivatizationof the amines and polyamines with MCA and SVS yields a further crop ofamine buffers with desirable properties. MCA and sodium monochloroaceticacid (SMCA) can be used interchangeably.

The reaction of tromethamine as described above yields the products inFIG. 1. In step 1 in FIG. 1 where the acrylonitrile is added to theamine a branched structure wherein the addition of acrylonitrile resultsin a tertiary amine is shown. In reality, particularly when n is greaterthan 1, a mixture of products is obtained that is both tertiary andsecondary. For the invention disclosed herein, n may equal any integergreater than zero, including 1. Controlling the reaction temperature,pressure and agitation will allow the mixture to be predominatelysecondary (such as when m=n) or tertiary amine, m can be any integerless than or equal n. Furthermore, this selection can take place inadding acrylonitrile to the amine that results, allowing a progressivelymore branched product. It is within the scope of the invention disclosedherein to include these additional types of products and theirsubsequent derivatives described herein.

With regard to the reaction of the polyamine resulting from the secondstep in FIG. 1. FIG. 1 shows the addition of only one mole of SVS orMCA, it is known in the art, that a second mole may be added to obtain aproduct with a second zwitterionic group. Furthermore, in the case wherethe product has repeated additions of acrylonitrile and reduction to theamines, the branched products may have many more zwitterionic groups.Also, it is to be noted that, while the sulfonates are shown as sodiumsalts, other salts and the free acids (non-salted form) are also withinthe scope of this invention.

Other amines that would make excellent starting materials in place oftromethamine are 2-amino-2-methyl-1-propanol, 2-amino-1-butanol,2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, anddihydroxymethylaminomethane.

Additionally, fatty amines, such as lauryl amine, coco amine, tallowamine, and oleoyl amine, and fatty ether amines, such asbis-(2-hydroxyethyl)isodecyloxypropylamine, when reacted with SVSproduce mild surfactants that find utility where zwitterionicsurfactants are desired, including personal care.

Other amines that are shown in FIG. 2 are produced via a similar seriesof reactions, except that FIG. 2 includes zwitterionic buffers from theamine 2-amino-2-methyl-1-propanol, as well as the polyamines derivedfrom the reaction with acrylonitrile and the subsequent derivativesdescribed above. Other amines can be utilized in addition to2-amino-2-methyl-1-propanol to obtain excellent buffers are2-amino-1-butanol, 2-amino-2-ethyl-1,3-propanediol,2-amino-2-methyl-1,3-propanediol, and dihydroxymethylaminomethane.Reaction conditions could be created such that the alcohol groups on theamines listed above could be reacted with acrylonitrile as well, andthen reduced to the amines and, if desired, reacted with SVS or MCA toimpart zwitterionic character.

Polyamines with good properties for use in biological fermentations,purifications, storage and general handling can also be produced throughthe reaction of nitroalcohols and acrylonitrile, followed by reduction.Additional derivatization with SVS or MCA will result in zwitterionicbuffers with a very large buffering range and capacity.

FIG. 3 shows the reaction of 2-methyl-2-nitro-1-propanol withacrylonitrile and its derivatives.

FIG. 4 shows the reaction of 2-nitro-2-ethyl-1,3-propanediol withacrylonitrile and its derivatives where x, y, and n are all integerswhere x and y are chosen independently, such that x+y=n and n is greaterthan zero.

FIG. 5 shows the reaction of 2-nitro-2-methyl-1,3-propanediol withacrylonitrile and its derivatives where x, y, and n are all integerswhere x and y are chosen independently, such that x+y=n and n is greaterthan zero.

FIG. 6 shows the reaction of tris(hydroxymethyl)nitromethane withacrylonitrile and its derivatives where x, y, z, and n are all integerswhere x, y and z are chosen independently, such that x+y+z=n and n isgreater than zero.

FIG. 7 shows the reaction of 2-nitro-1,3-propanediol with acrylonitrileand its derivatives where x, y, and n are all integers where x and y arechosen independently, such that x+y=n and n is greater than zero.

FIG. 8 shows the reaction of 2-nitro-1-butanol with acrylonitrile andits derivatives.

FIGS. 2 through 8 are subject to the same clarifications as FIG. 1 withregard to the cyanoethylation and the formation of a more linear orbranched structure as well as the addition of SVS or MCA in molarequivalents of primary amine groups or less than molar equivalents ofprimary amine groups present.

The buffers described thus far may also be ethoxylated, propoxylated, orbutoxylated to modify their properties. Ethoxylation will tend to impartsurfactancy to the resulting product. Propoxylation will addsurfactancy, but also reduce the water solubility. This is useful inemulsion breaking and reverse emulsion breaking, this will also findutility in breaking up and dissolving biofilms. This is also desired inoil-field applications. Butoxylation will similarly shift the HLB to thehydrophobic. Combinations of ethoxylation, propoxylation, andbutoxylation can be tailored to specific emulsion and reverse emulsionforming and breaking requirements. FIG. 9 shows alkoxylation ofaminomethylpropanol. The direct 2 mole ethoxylation of2-amino-2-methyl-1-propanol with 2 moles of ethylene oxide, as shown inFIG. 9 produces an excellent biological buffer with less chelation than2-amino-2-methyl-1-propanol. The reaction of 2-amino-2-methyl-1-propanolwith propylene oxide or butylene oxide yields a similarly less chelatingproduct, as does the reaction with diethylene glycol. The reactionproduct of 2-amino-2-methyl-1-propanol with 1 mole of diethylene glycolas shown in FIG. 9 produces an ideal amine for gas scrubbing of H₂S.This product is particularly useful because it does not bind to carbondioxide and carbon monoxide in any appreciable amount. Thus making itideal for tail gas scrubbing and maximizing the capacity of sulfurplants in refineries. Similar performance is seen with the reaction ofthe following amines 2-amino-1-butanol,2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol,tris(hydroxylmethyl)aminomethane, and 2-amino-1,3-propanediol.

The buffers described herein also make excellent starting materials forsurfactants. FIG. 10 shows the synthesis of two very mild, high foaming,surfactants that are well suited for personal care applications wereirritation is problematic, such as baby shampoo and face cleansers.Similar results are seen when 2-amino-1-butanol,2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol,tris(hydroxylmethyl)aminomethane, and 2-amino-1,3-propanediol are usedas the starting material in place of 2-amino-2-methyl-1-propanol.

Polyamines with good properties for use in biological fermentations,purifications, storage and general handling can also be produced throughthe reaction of nitroalkanes and acrylonitrile, followed by reduction.Additional derivatization with SVS or MCA will result in zwitterionicbuffers with a very large buffering range and capacity. FIG. 11 showsthe synthesis of a series of buffers with 2-nitropropane as the startingmaterial. FIG. 12 shows the synthesis of a series of buffers with1-nitropropane as a starting material where n and m are integers wherem+n is greater than zero and n is greater than or equal to m. Branchingcan be imparted on the buffers described in FIGS. 11 through 14 for thepolyamines that have greater than 3 amine groups by reducing theresulting nitrile or polynitrile to the polyamine and then reacting withmore acrylonitrile and then reducing the resulting nitrile groups toamine groups. This can be done repeatedly. As in FIG. 1, conditions canbe chosen such that a more branched product results. A more linearproduct is produced by simply adding all the acrylonitrile in one step,and then reducing the resulting polynitrile to the polyamine. For FIGS.12 through 14, the zwitterionic products can be made by adding MCA orSVS as shown in FIGS. 2 through 8.

FIG. 13 shows the synthesis of a series of buffers with nitroethane as astarting material where n and m are integers where m+n is greater thanzero and n is greater than or equal to m. FIG. 14 shows the synthesis ofa series of buffers with nitromethane as a starting material where x, y,z and n are integers and x+y+z=n and n is greater than zero.

Several descriptions and illustrations have been presented to enhanceunderstanding of the present invention. Numerous changes and variationsare possible without departing from the spirit of the invention. Each ofthese changes and variations are within the scope of the presentinvention.

Another embodiment of the present invention is the synthesis ofzwitterionic buffers with vinyl acids. FIG. 15 shows the synthesis of afamily of zwitterionic buffers based on members of the acrylic acidfamily. However, other vinyl acids may be used. Vinyl acids such asacrylic, 3-butenoic acid, 4-pentenoic acid, and other carboxcylic acidswith a double bond at the terminus. Carboxcylic acids with a triple bondat the terminus also can be utilized, similarly, an acid where themultiple bond is not at the terminus, such as hex-4-enoic acid, can alsobe utilized. However, due to the reduced commercial availability of suchcompounds, the preferred embodiment is the vinyl acid with a double bondat the terminus. One very large benefit of utilizing vinyl acids to makezwitterionic buffers is that the product does not need to be ionexchanged to produce a non-ionized form. In the market, both ionized, orsometimes called salted, and non-ionized forms sometimes called freeacid or free base, are required. In situations where ionic strength mustbe very closely controlled, the non-ionized forms are more popular. Forcases where increased water solubility and ease of solution are desired,the salted forms are preferred. The present invention covers both theionized and non-ionized forms of the buffers disclosed herein.

Another embodiment of the present invention is the sulfonatezwitterionic buffers derived from the reaction of an amine with anepichlorohydrin and sodium bisulfate condensate as described in FIG. 16.Other sulfate salts can be utilized to arrive at the desired molecularstructure and is included in the present invention. FIGS. 17 through 25teach the flexibility of the present invention to synthesize a series ofa amine sulfonate or amino acid zwitterionic buffers from nitroalcoholsor alkanolamines to produce zwitterionic buffers that have primary aminofunctionality or secondary amino functionality. In cases where there aremore than one reactive group, amine, alcohol, or a combination, multiplesulfonate groups or acid groups can be reacted by adding more than oneequivalent of the vinyl acid or the oxirane containing sulfonate.

Another embodiment of the current invention is to make zwitterionicbuffers with cycloamines as the starting material. The cycloaminesresult in a tertiary amino group that is less chelating and interferesless in biological functions. FIG. 26 shows the reaction of morpholinewith a vinyl acid and morpholine with the oxirane sulfonate. FIG. 27teaches similar products, but utilizing hydroxyethyl piperazine. FIG. 28teaches the use of diamines as starting materials by using piperazine asthe starting material. This is a good example of a synthesis ofpolyzwittterionic buffers as discussed earlier. FIG. 29 teaches the useof ethylene amines to make zwitterionic buffers through reaction withvinyl acids or oxirane sulfonates. Similar compounds can be made byusing ethylene amines, such as monoethanolamine and the higher homologs,such as diethylenetriamine and is part of the invention disclosedherein.

Another embodiment of the current invention is the synthesis ofzwitterionic amines that have primary, secondary, tertiary, andquaternary amine functionality. FIG. 30 teaches this via oxiranesulfonate and amines. It is obvious to one in the art that any primary,secondary, or tertiary amine can be used in place of the methyamines inFIG. 30. While not shown in the figure, the resulting amines can bereacted further with vinyl acids, monochloroacetic acid, sodium vinylsulfonate, or an oxirane sulfonate to further add acidic character tothe zwitterionic buffer.

Another embodiment of the current invention is the synthesis of mildsurfactants from nitroalcohols. FIGS. 31 through 33 teach the synthesisof these mild surfactants. Lower molecular weight acids produce lowerfoaming mild surfactants, whereas higher molecular weight carboxcylicacids yield higher foam. Lauric acid is the preferred embodiment for ahigh foaming, mild surfact. Coconut fatty acid performs similarly, butat a lower cost. A good surfactant with low foam can be made usingoctanoic acid as the carboxcylic acid.

Another embodiment of the current invention is the synthesis ofpolyamines from nitroalcohols. FIGS. 34 and 35 teach the synthesis ofdiamines from nitroalcohols. FIG. 34 teaches the synthesis with severalhydroxyl groups present. Additional amino groups can be added byreacting more than one equivalent of epichlorohydrin to thenitroalcohol, up to the number of hydroxyl groups, and then reacting thesame number of equivalents of amine to the oxirane containing amine. Inthe case where the nitroalcohol is reduced to the amino alcohol in thebeginning, the addition of base, such as caustic, to the amino alcoholwill assist in the reaction of the epichlorohydrin with the hydroxylgroups. Without the base, the epichlorohydrin will preferably react withthe amine as outlined in the 1 equivalent addition depicted in FIG. 34and FIG. 35. FIG. 26 demonstrates that tertiary amines can be used tomake zwitterionic buffers with quaternary amine functionality fromtertiary amines. While not explicitly shown, any other tertiary aminecan be used as the starting material and is part of the inventiondescribed herein. FIG. 37 and FIG. 38 demonstrate that diamines can bemade from nitroalcohols by reacting sequentially the nitroalcohol withepichlorohydrin and then the second equivalent of the nitroalcohol,followed by reduction. Also taught is that a reduction step can takeplace in the beginning to yield a diamine with two secondary aminogroups. The nitroalcohols or alkanolamines do not need to be symmetric,but others may be used in the synthesis of the diamine and is part ofthe invention disclosed herein.

As outlined earlier, the resulting amines can be reacted further withvinyl acids, monochloroacetic acid, sodium vinyl sulfonate, or anoxirane sulfonate to further add acidic character to the zwitterionicbuffer.

Several descriptions and illustrations have been presented to enhanceunderstanding of the present invention. One skilled in the art will knowthat numerous changes and variations are possible without departing fromthe spirit of the invention. Each of these changes and variations arewithin the scope of the present invention.

1. A biological buffer of the following structure:

Where x is from 3 to
 8. 2. A Biological Buffer of the following structure:


3. A Biological Buffer of the following structure:

Where A is chosen from the group H, —OH, —CH₃, and —CH₂CH₃, and where D is from the group H, —CH₃, —CH₂CH₃.
 4. A Biological Buffer of the following structure:

Where A is chosen from the group —OH, —CH₃, or —CH₂CH₃.
 5. A Biological Buffer of claim 4 where A=—OH.
 6. A Biological Buffer of claim 4 where A=—CH₃.
 7. A Biological Buffer of the following structure:

Where A is chosen from the group —H, —OH, or —CH₂CH₃.
 8. A Biological Buffer of claim 7 where A=H.
 9. A Biological Buffer of claim 7 where A=—OH. 